Punishment for sneaking a peek?

If an 18 yr. old boy sneaks a peak at his Christmas gift (iPod) (you know this because of moved packages etc.) what, if any, should be the punishment?

I say don’t include the iPod in gifts under the tree- wait until he unwraps the last present to find no iPod and watch him squirm….maybe let him have it a week later or something. Thoughts?